Topcon ES-65 - Optical Plummet

18-6
18 CHECKS AND ADJUSTMENTS
5) Do the calculations:
A2-A1 and B2+B1
If A2-A1 is within 180°±20″and B2(B1 is within 360°±40″,
adjustment is unnecessary.
Example:
A2-A1 (Horizontal angle) =198° 34' 20"- 18° 34' 00"
=180° 00' 20"
B2-B1 (Vertical angle) =269° 30' 00" + 90° 30' 20"
=360° 00' 20"
If the difference is large even after repeating the check 2 or
3 times, make sure that checking and adjusting of Section
18.2 “Adjustment of Vertical Angle 0 Datum” and
“Adjustment of Compensation Systematic Error of
Instrument” are completed.
If the results remain the same, have our service
representative perform the adjustment.
18.5 Optical Plummet
 Checking
1) Carefully level the ES and exactly center a survey point in
the reticle of the optical plummet.
2) Turn the upper part 180
° and check the position of the
survey point in the reticle.
If the surveying point is still centered, no adjustment is
necessary.
If the surveying point is not still centered in the optical
plummet, adjust as follows:
 Adjusting
3) Correct half the deviation with the levelling foot screw.
4) Firmly hold down the top portion of the instrument, and
remove the optical plummet knob cover, then remove the
optical plummet reticle cover on the inside.
Replace the optical plummet knob cover.
Use the 4 adjusting screws of the optical plummet to adjust
the remaining half of the deviation as show below.
Optical plummet
reticle cover
Optical
knob cover
plummet